The invention disclosed herein pertains to a device for positioning bottles symmetrically to the rotational axis of bottle carriages in labeling machines and the like wherein the bottle is rotated about a vertical axis when a label is being applied.
German Patent DE-PS 2419133 discloses a device for aligning and centering cylindrically shaped bottles which have a central depression or recess at their bottoms that provides for achieving alignment and centering of the bottle with an axis of rotation on a bottle carriage. In this device the bottles are centered by reason of a cone registering in the recess. Bottles which have this recess can be centered and aligned in preparation for having a label applied to them while they were rotating independently of their outer contour and shape. Devices designed in this manner are preferred for labeling machines which must be capable of processing numerous containers of varying shapes without requiring time-consuming changeover work. It is not unusual for machines which are used to fill bottles with alcoholic beverages must be capable of handling up to 10 or more different types of bottles.
It is conventional practice to align the bottles on their center of rotation, during passage of the bottles through an alignment zone, by means of a vertically controllable centering cone which lifts the bottles slightly and rotates them until an alignment lug becomes engaged with the bottle. Rotation of the bottle can be accomplished by means of a frictional surface that acts directly on the periphery of the bottles or by means of a friction drive wheel that acts on and rotates the centering cone. In this known apparatus, problems can occur while the machine is operating partly as a result of the considerable difference in the dimensional tolerances of bottles and also as a result of the bottles having wet surfaces so that proper alignment and centering is not carried out in all cases. A further disadvantage in prior devices is that the frictional surface for driving the bottle depends on the shape of the bottle; that is, the frictional driving element must be exchanged when there is a change in bottles which have different shapes or sizes. A further disadvantage is that the frictional driving systems used in prior art bottle carriages exert lateral forces on the center bottles which is undesirable.
The control mechanism for moving the centering cone vertically is very expensive to construct and is considered disadvantageous because very little space is available in the rotary table which orbits the bottles as they pass a station at which a label is applied to a rotating bottle. This is especially true in arrangements wherein the centering cone is driven rotationally by an auxiliary friction belt that is arranged under the rotary table.